<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .continer{
        height: 100px;
        width: 140px;
       
    }
    .continer div{
        display: none;
        background-color: rgb(48,54,67);
         
    }
    .continer:hover div{
        display: initial;
    }
</style>
<body>
    <div class="continer">
        文字内容文字内容
        <div>我是悬停内容</div>
    </div>
</body>
</html>